package com.kuang.pc;

public class A {
    public static void main(String[] args) {
        Data data = new Data();

        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"A").start();
        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"B").start();

        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                    try {
                        data.decrement();
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
            }
        },"C").start();


        new Thread(()->{
            for (int i = 0; i < 10; i++) {
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        },"D").start();
    }
}
// 判断等待，业务，通知
class Data{ // 数字 资源类
    private int number = 0;
    //+1
    public synchronized void increment() throws InterruptedException {
        while (number!=0){ //0
// 等待
            this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName()+"=>"+number);
// 通知其他线程，我+1完毕了
        this.notifyAll();
    }
    //-1
    public synchronized void decrement() throws InterruptedException {
        while (number == 0) { // 1问题存在，A B C D 4 个线程！ 虚假唤醒
           // if 改为 while 判断
// 等待
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName() + "=>" + number);
// 通知其他线程，我-1完毕了
        this.notifyAll();
    }
    }
